A computing device may be capable of creating an image on a broad range of display devices. These display devices may be different sizes and have different image rendering capabilities. A user may wish to use multiple displays with a single computing device in order to increase that computing device's utility. For instance, a laptop may be connected to a television in order to show a video on a larger screen or to enhance image quality, or the laptop computer may be connected to two or more external display devices.
One particular use of multiple displays is in a multi-display setup. A multi-display setup involves the use of multiple physical display devices, such as monitors, projectors, tablets, and televisions in order to increase the area available for computer programs running on a single computer system. Typically, a multi-display setup will involve two or more physical display devices positioned so as to increase the available viewing area of the computer desktop.
The graphical user interface (GUI) of a computer may allow a user to draw and move windows on the display devices in a desktop environment through the use of a mouse, keyboard, touch sensor, or other input device. The user may be able to drag a window from one display screen to another display screen (of the same or different size, resolution, aspect ratio and color capabilities), using a window manager program such as Microsoft™ Desktop Window Manager. The Desktop Window Manager (DWM) program in Microsoft® Windows® operating system will typically control the placement and appearance of windows within the desktop environment. Multiple-display desktop environments have many well-known features and advantages.
The physical display devices used in a multi-display setup may be different types (liquid-crystal display, cathode ray tube, etc.) and sizes. The displays may have different capabilities with regards to resolution, color, or refresh rate. The operating system typically will manage the physical display devices independently.
Generally, when a computing device utilizes multiple displays of different resolutions, sizes, or capabilities, a window transferred from one display device to another display device will have a somewhat different appearance on each display. For example, when moving a window from a high resolution display to a low resolution display with a known window manager, when each display is of equal physical dimensions, the window will be much smaller on the high resolution display than the low resolution display. Alternatively, a computing system with a known window manager may operate so that a window will take up the same proportional size of the screen on the first and second display, regardless of the resolution.
A user may be able to change display settings of a window. Colors may be changed from normal to high contrast modes to assist a user reading text. Content may be enlarged in a uniform or nonuniform manner within the window. For example, some web browsers allows for the selection of a minimum font size, as well as an ability to increase the size of both the font and images. Changing these and other display settings may allow a user to optimize viewing preferences on displays with different display capabilities.